Gloves are commonly used to protect hands in an industrial or household environment. The gloves, upon wearing, fill with sweat and feel clammy to the user. Advances in glove manufacturing technologies have resulted in partial coating of a fabric knitted liner with an adherent latex layer on the working side so that glove is breathable in the exposed non-latex layer, knitted areas.
Generally, knitted liners are fabricated from relatively thick robust yarns having 319 denier, (a denier defined as number of grams of a 9000 meter yarn) or greater using 15-gauge knitting needles or larger needles. Knitting machines are designed with a needle gauge specified. For example, a 15-gauge V-bed knitting machine has these 15-gauge needles spaced such that there are 15 needles per inch. Similarly, a 10-gauge needle machine has 10-gauge needles spaced such that there are 10 needles per inch. A 15-gauge needle may generally use a 319 denier yarn for knitting. A smaller size yarn such as a 221 denier yarn is typically suited for an 18-gauge needle. Knitted stitches of 319 denier yarn using a 15-gauge needle will be spaced further apart than knitted stitches of 221 denier yarn using an 18-gauge needle. Regardless of the gauge of needles used, a knitted liner with 221 denier yarn is lighter in weight, thinner and more flexible than a knitted liner with 319 denier yarn. Lighter weight knitted liners are needed to produce lightweight gloves.
When 319 denier yarn is knitted with a 15-gauge needle, the liner created is thick. A latex layer that coats such a liner is also correspondingly thick resulting in a glove with a heavy feel that has limited flexibility. When a foamed, porous latex layer is used in order to provide breathability, the resulting thickness of this porous latex layer generally results in an awkward-feeling glove with limited touch sensitivity. For equivalent wear resistance, the foam layer must be thicker than a non-foamed layer. A number of prior art patents address gloves and their forming methods using relatively thick knitted liners and thick coatings of latex layers. A combination of a thick knitted liner and a thick foamed latex layer does not result in a small overall glove thickness and the resulting glove does not provide flexibility and easy mobility of fingers and hand. Moreover, for a glove having a coating, the coating is susceptible to cracking and deterioration at areas of high stretch and movement, such as, the areas at the base of the fingers and thumb and within the palm area.
U.S. Pat. Nos. 4,514,460 and 4,515,851 to Johnson disclose slip-resistant surfaces. U.S. Pat. Nos. 4,555,813 and 4,567,612 to Johnson discloses slip-resistant gloves. U.S. Pat. Nos. 4,569,707 and 4,589,940 to Johnson disclose methods of making foamed slip-resistant surfaces. This porous surface is particularly useful for workers in work environments wherein the gloves are breathable and have moisture-absorbing properties. The surface is a foam surface laminated to a knitted or woven web substrate. The polyurethane, polyvinyl chloride, acrylonitrile; natural rubber, synthetic rubber foam, prior to lamination, may be foamed with varying amounts of air depending upon the degree of abrasion resistance required. The foaming may be by mechanical or chemical means.
U.S. Pat. Nos. 4,497,072 and 4,785,479 to Watanabe disclose porous coated glove and method of making a glove. Broken air bubbles form the porous surface. The air cells are closed and provide cold protection and waterproof qualities. The thick closed cell foam is bonded to woven or knitted sewn fabric. Due to its cold protection properties this is a thick glove with minimal flexibility.
U.S. Pat. No. 5,581,812 to Krocheski discloses a leak proof textile glove. A cotton glove is inverted and dipped in a PVC or polyurethane latex solution to make the cotton glove impervious to water or oil. The glove is inverted so that the cotton surface is the gripping surface while the latex layer contacts the skin. The latex layer may be optionally flocked to provide a better skin feel. There is no knitted liner in this glove. The latex layer applied is impervious to water or oil, but is not breathable.
U.S. Pat. No. 6,527,990 to Yamashita et al. discloses a method for producing a rubber glove. The rubber glove is made by sequential immersion of a glove mold in coagulating synthetic rubber latex that contains thermally expansible microcapsules. During the vulcanization of the synthetic rubber latex, these microcapsules burst providing excellent anti-blocking and grip under wet or dry conditions. There is no knitted liner in this glove and the latex layer completely surrounds the hand.
U.S. Patent Publication No. 2002/0076503 to Borreani discloses a clothing article such as a working or protective glove made from textile support. The textile support receives an adherence primer in the form of an aqueous calcium nitrate. The textile support with the adherence primer is coated with a foamed aqueous polymer, preferably an aliphatic polyether urethane or polyester urethane entirely or partially. The foamed aqueous polymer only appears on the support outer part without going through the textile support mesh. When the textile support is too hydrophilic, 2-5% fluorocarbon is added to the aqueous latex emulsion. The size of the yarn in the textile support is not indicated. The patent does not indicate why the aqueous polymer does not penetrate the textile support mesh. The viscosity of the aqueous air foam is in the range of 1500 to 3000 centipoise and this thick foam may not enter the mesh, but only contacts the fibers at very localized regions creating a poor bond between the polymeric layer and the textile support.
U.S. Patent Publication No. 2004/0221364 to Dillard et al. discloses methods, apparatus, and articles of manufacture for providing a foam glove. A textile shell is coated with a foamed polymeric coating that is supported in part by the surface of the textile shell. Sufficient amount of air mixed with the base polymer to lower the density of the base polymer between about 10 to 50% of the original density of the base polymer. The textile shell is knitted using nylon, polyester, aramid, cotton, wool, rayon or acrylic fibers. The foam cells absorb liquid, which indicates that the foamed polymer does not protect the hand from water or oil present on the object being gripped. The yarn is said to be knitted with a 15-gauge needle using a Shima Seiki knitting machine that fixes the size of the knitted textile shell to be a thick shell, not a thin shell. As a result, the foam glove is a thick product and is not very flexible.
The knitting technology of V-bed machines have improved significantly in the past few years. Knitting needles in the knitting machine were essentially a hook with a swingable latch that captured a yarn that was being knitted, but this knitted loop could not be held or transferred back or combined with a previously knitted loop. U.S. Pat. No. 6,915,667 to Morita, et al. discloses a composite needle of knitting machine. This composite needle comprises a needle body having a hook at a tip end and a slider formed by superposing two blades. The composite needle of the knitting machine is formed such that a blade groove provided in the needle body supports the blades of the slider when the needle body and the slider can separately slide in forward and backward directions. This slider acts as a latch securing the yarn being knitted and can transfer the yarn loop for pushing the loop backwards, holding the loop or transfer back to a previously knitted loop. Complex patterns that can be achieved are detailed by the Shima Seiki web page http://www.shimaseiki.co.jp/product_knite/knite.html. This type of composite needle is available in Shima-Seiki commercially available whole garment knitting machines SWG021/041 and SWG-FIRST machines. The SWG-FIRST machines provides gaugeless knitting, meaning that the number of needles may be changed on the fly under computer control seamlessly by using split stitch technology, as detailed in U.S. Pat. No. 7,207,194 to Miyamoto titled ‘Weft knitting machine with movable yarn guide member’.
Knitted liners that are shaped according to the anatomical shape of a human hand for improved fit are disclosed in U.S. Pat. Nos. 6,962,064; 7,213,419; and 7,246,509 to Hardee, et al. These knitted liners are made to fit human hand shape by changing the knitted loop length under computer control, or changing the yarn tension.
U.S. Patent Publication No. 2007/0022511 to Narasimhan et al. discloses selective multiple yarn reinforcement of a knitted glove with controlled stitch stretch capability. The controlled stitch stretch is provided by a variable stitch dimension and is accomplished by 1) varying the depth of penetration of the knitting needle into fabric being knitted by a computer program, 2) adjusting the tension of yarn between a pinch roll and knitting head by a mechanism controlled by a computer and 3) casting off or picking up additional stitches in a course.
Accordingly, there is a need in the art for robust durable thin lightweight highly flexible latex gloves that have the latex layer applied to a lightweight knitted liner at work-contacting portions of the glove surface. There is also a need to provide gloves having reinforcement sections to provide enhanced flexibility and integrity to withstand repeated flexure. It is also desirable to have a latex layer that is porous providing additional breathability and improved flexibility.